Summary Report No. 62

Future
climate change will most likely affect the composition of plant
communities in the forests of Brandenburg. Results from the forest
simulation model FORSKA show significant vegetation changes for
climatic warming scenarios. The objective of this investigation was to
analyse how these vegetation changes impact forest functions.

The impacts on the forest functions were evaluated based on the
change of the simulated species composition of the potential natural
vegetation. The forest functions were evaluated using empirical and
statistical methods, which were previously used primarily for landscape
planning under current climatic conditions. Forest functions considered
were species and habitat conservation, groundwater recharge, and carbon
sequestration. Species and habitat conservation was divided into
several components: species richness, structural variety, spatial
diversity and vegetation endangerment. An aggregated diversity index
was calculated for biogeographical subregions with similar climate and
site characteristics.

The results indicated a shift of plant communities towards a greater
share of drought tolerant species in response to climatic warming. The
assessment of forest functions showed that the aggregated diversity
index, groundwater recharge and carbon sequestration decreased
significantly with climate change. No characteristic regional pattern
was recognizable.

The applied methods used to evaluate the impacts of climate change
were developed for current climate conditions. This must be considered
when the results of the regional impact assessment are interpreted. In
further groundwater recharge studies, consideration should be given to
the influence of higher temperatures and CO2 content in the
air. These change the evapotranspiration and water use efficiency of
the plants. The habitat diversity function was evaluated using data
from representative forest ecosystems. It should be noted that there is
high uncertainty how ecosystems characteristics such as species
richness and stand structure will develop under a changing climate.

This was a first attempt to analyse the impact of climate change on
different forest functions. The results indicate that the investigated
forest functions are quite sensitve to climate change in Brandenburg.
It is concluded that the evaluation of forest functions is important in
developing management strategies to mitigate negative impacts of
climate change on forests in Brandenburg.